This invention relates to a lock for a movable wing, and particularly to a lock intended to be rim fitted to a domestic entrance door.
According to the invention a lock for a wing movable between open and closed positions relative to a frame comprises a casing, a bolt operable to extend from or to retract into said casing, a housing extending from one side of the casing, a lock cylinder at least partly received in said housing, fixing means at said housing securing said lock cylinder to said housing, and cover means preventing access to said fixing means, release of the cover means to allow access to said fixing means for releasing the securement of the lock cylinder to the housing only being possible from the opposite side of the casing.
Preferably the cover means is secured at least partly around, and more preferably wholly around, the housing, and desirably the cover means is secured against said one side of the casing. Conveniently said cover means is a rose. Advantageously said cover means is secured in place by at least one fixing screw passing from inside the casing into a threaded bore in an underside of the cover means, and most preferably access from said interior of the casing to the or each fixing screw is only possible when the bolt is in a retracted position.